Are you skinny-fat?

ACTIONS NOT APPEARANCES: You may be skinny but what you eat still affects your health.
ACTIONS NOT APPEARANCES: You may be skinny but what you eat still affects your health.

You might be the envy of your mates as you make a meal out of meat pies and beers while still slipping into your skinny jeans. But, external appearances aren't everything and your insides might not be looking so crash-hot.

Obesity is epidemic, but for all the focus on fat and striving to be skinny, we may have forgotten the fundamental point.

This is because the fat cop flak for being "unhealthy" and the skinny are benchmarked as beautiful examples of health when this is not necessarily the case.

"There's no point being 'healthy' and thin if you're being unhealthy to do it," says Dr Ginni Mansberg.

In fact, increasingly, experts are warning against using external appearances as the barometer for internal health.

A new report by the Mayo Clinic says there is a "need for an updated definition of obesity based on adiposity, not on body weight".

In the paper, published in the journal Progress in Cardiovascular Diseases, the researchers say that those with normal body weight but high body fat percentage show a high degree of metabolic dysregulation.

This phenomenon, "defined as normal-weight obesity", is associated with a significantly higher risk of developing diabetes, cardiovascular disease and of premature death, the authors say.

Being skinny-fat or a TOFI (thin outside, fat inside) is not unusual. In fact, it is "extremely common", says Associate Professor Amanda Salis, from the Boden Institute of Obesity, Nutrition, Exercise and Eating Disorders.

One 2007 study of 800 people found up to 45 per cent of those with normal body mass index (BMI) scores (20 to 25) had too much internal fat. This figure increased to 60 per cent in the men.

"Skinny-fat is really referring to fat around the organs and fat in the bloodstream," says Professor Salis, who points out that it is not, as it is commonly misinterpreted to be, a reference to thin women with wide hips or big bums.

It is from having fat around the organs, that someone can have model proportions and still be internally unhealthy.

Despite this, it is also true that it is rare to be fat and fully fit.

new review of studies looking at 61,386 individuals since the 1950s found that simply being overweight, healthy or not, increases your risk of heart disease and premature death.

"Skinny-fat is not carte blanche for people who are overweight not to have to do anything about it because 'those skinny people over there are far more unhealthy than I am'," Dr Mansberg says, pointing out that excess weight is linked to poorer mental as well as physical health.

"We can't think that we can be fat and fit," Professor Salis adds. But, "there is strong truth that you can't just look at BMI either".

She explains that while BMI is an effective tool for looking at the general health of a population, it is less effective when looking at individuals, as we can see with skinny fat as well as some races and athletes, whose muscle mass pushes them into the "unhealthy" BMI range.

While body weight is part of the puzzle, diet and fitness are equally important.

"Fitness never goes out of style," Salis says. "There is no debate about that."

We need incidental activity for general health, strength training for muscle mass and aerobic training for cardiovascular health, she explains.

As for diet, Professor Salis says: "The foods we eat on a regular basis promote metabolic health."

Dr Mansberg adds that it is about having a generally healthy diet, "which isn't to say you can't have anything sinful ever, just don't live on those foods".

That said, she points out that some people have sensitivities to certain foods or alcohol and need to be more careful about how much they consume.

But, skinny, fat or skinny-fat, just because we can't "see" the impact, it doesn't mean that any of us can get away with treating our bodies badly.

Appearances are often just that and it truly is a case of what's inside that counts.

As Dr Mansberg says: "People who abuse their bodies because they can, from a looks perspective, need to remember, just because you're skinny, your family history still matters, alcohol and diet still matters, the amount of exercise you do still matters and your waist circumference still matters."

Sydney Morning Herald